1. In a large stockpot, bring broth & water to a boil on medium-high. Add potatoes & simmer 7 minutes or until almost tender.
2. Add barley, greens, mushrooms, garlic & pepper flakes. Mix well & simmer 5 minutes.
3. Add chicken & pepper. Simmer 5 minutes or until chicken is cooked through.
4. Divide soup evenly into serving bowls, top with cheese & serve immediately!